Lightweight Design of CFRP Automobile Tailgate Based on Multi-Step Optimization 2019-01-1103

As a critical part of auto-body, the design of tailgate not only affects the beauty, usability and safety of automobile, but also involves more and more issues about environmental protection and energy saving. Hence, it is of vital importance to investigate lightweight of tailgate.

This paper mainly focuses on lightweight design of CFRP tailgate based on conventional SUV metal tailgate, which can be realized under the condition of meeting requirements of stiffness, modal and manufacturing with the adoption of multi-step optimization method. To start with, finite element (FE) model of metal tailgate is established. Meanwhile, the stiffness and modal analyses, including bending stiffness, torsional stiffness, lateral stiffness, vertical stiffness and free modal are set up. Then, the structural performances of metal tailgate are analyzed, and the topology optimization of CFRP tailgate is performed. Subsequently, based on the topology optimization results and layup principle of composites, the redesign and FE modeling of CFRP tailgate are carried out. Owning to the large optimization space, the optimization of free size, size and stacking sequence is further performed to achieve superior lightweight potential.

Eventually, the performances of the optimized CFRP tailgate and metal tailgate are compared to verify the lightweight effect. The results show that the weight of CFRP tailgate is reduced by 37.44% compared with that of metal, while at the same time the stiffness and first-order modal frequency have been improved.